Microchemical Journal最新文献

{"title":"Primer exchange reaction catalyzed DNA walker cooperating target recycling for sensitive and reliable microRNA analysis","authors":"Huajun Wang,&nbsp;Hang Zhang,&nbsp;Xueda Wu,&nbsp;Fengwu Shi,&nbsp;Jinghui An","doi":"10.1016/j.microc.2025.115177","DOIUrl":"10.1016/j.microc.2025.115177","url":null,"abstract":"<div><div>MicroRNAs (miRNAs) have gained significant attention as potential biomarkers and therapeutic targets for cardiovascular diseases (CVDs). However, the sensitive detection of miRNAs in complex biological samples remains challenging due to their low abundance and interference from non-specific targets, despite its critical importance for biopsy analysis and disease diagnosis. In this study, we developed a self-priming DNA polymerization-initiated PER-driven DNA walking system for the highly sensitive detection of miRNA targets in complex biological matrices. The sensing system was immobilized on a plate surface, which not only provides a three-dimensional interface for DNA walkers but also enhances the enrichment and isolation of RNA targets from complex samples such as serum. The DNA walking system is activated by target recognition-mediated self-priming DNA polymerization, enabling the walker to traverse the plate surface through primer exchange reaction (PER) catalysis, thereby converting RNA targets into amplified fluorescence signals. This platform offers ultra-high sensitivity with a detection limit of 0.76 fM for miRNA-21, enabling precise measurement even in complex biological samples. It also provides excellent specificity through a label-free ThT-based fluorescence mechanism, effectively distinguishing target miRNAs from homologous sequences without the need for complex labelling. This platform holds significant promise for applications in RNA bio-sensing and biomedical diagnostics.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115177"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Predictive modeling and chemometric optimization in natural dyeing systems: An analytical case study of wool dyeing with Melissa officinalis L","authors":"Siyamak Safapour ,&nbsp;Tuba Toprak-Cavdur ,&nbsp;Fatih Cavdur ,&nbsp;Luqman Jameel Rather ,&nbsp;Mohammed A. Assiri ,&nbsp;Qaiser Farooq Dar ,&nbsp;Qing Li","doi":"10.1016/j.microc.2025.115200","DOIUrl":"10.1016/j.microc.2025.115200","url":null,"abstract":"<div><div>This study introduces a robust chemometric framework that integrates predictive modeling and multi-criteria decision-making for the analytical assessment of natural dye systems. Using <em>Melissa officinalis</em> L. as a model extract, we demonstrate an eco-conscious dyeing application on wool yarns evaluated through objective colorimetric parameters. A total of 40 treatment combinations involving bio- and metal mordants were assessed. The Weighted Aggregated Sum Product Assessment (WASPAS) method was used to rank treatments based on L*, a*, and b* values, identifying the Cu-GA combination as optimal with a composite score of 1.71. To model dyeing behavior, we implemented a feedforward Artificial Neural Network (ANN) trained on 3720 K/S data points across treatment and wavelength conditions. The ANN achieved high predictive accuracy (R² = 94.13–95.28; MSE = 1.37–1.95) using Levenberg–Marquardt backpropagation. This model enabled the interpolation of unmeasured color strength values, enhancing reproducibility and reducing experimental load. UV protection was also evaluated, with the Cu-GA treatment achieving a maximum UPF of 128.43. Enhanced wash, rub, and light fastness in Fe and Cu mordanted samples were explained via coordination bonding between dye chromophores and fiber. These results demonstrate how machine learning and decision science tools can generalize analytical predictions in dye systems. The integrated ANN–WASPAS framework offers a transferable analytical strategy applicable to broader natural product formulations, quality control, and sustainable materials research.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115200"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Colorimetric detection and quantification of the stress-associated microRNA408 in tomato leaf extracts through RNAzymes in a paper-based microfluidic device","authors":"F. Nicolas Nazar ,&nbsp;Stefania Pellegrini ,&nbsp;Enrique Azuaje-Hualde ,&nbsp;Xabier Arciniega ,&nbsp;Pablo E. Guevara-Pantoja ,&nbsp;M. Carmen Marqués ,&nbsp;Francesca Longo ,&nbsp;Gustavo Gomez ,&nbsp;Lourdes Basabe-Desmonts ,&nbsp;Fernando Benito-Lopez","doi":"10.1016/j.microc.2025.115148","DOIUrl":"10.1016/j.microc.2025.115148","url":null,"abstract":"<div><h3>Background</h3><div>Timely detection of stress mediators in crops is crucial for preventing significant losses and optimising agricultural production, facilitating implementation of appropriate management strategies aligned with long-term food security. MicroRNAs (miRNAs) regulate stress responses by modulating gene expression, offering insights into crops' adaptive mechanisms. RNAzymes-catalytic RNA molecules-can be tailored to bind specific miRNA sequences, producing a colorimetric signal for accurate miRNA detection and quantification. miRNAs' detection with RNAzymes offers a promising strategy to monitor crop stress. This work presents a hybrid paper/plastic-based device for detecting stress response mediators in plants using RNAzyme-based colorimetric sensors.</div></div><div><h3>Results</h3><div>Specific RNA Sensing Probes were designed for miRNA408, a key stress marker in crops, using tomato plants as a model. After successful RNAzyme sensor design in solution, the sensor was transferred to a wax-ring-delimited paper area. The Sensing Probes exhibited activity on their own, and it was observed that the addition of miRNA408 induced a decrease in the colour signal intensity. Higher target concentrations (0–2560 ng in solution, 0–640 ng on paper) led to stronger inhibition and weaker colorimetric signals, with detection limits of 233 ng in solution (25 min) and 43 ng on paper (9 min). The sensor was then integrated into a microfluidic device and tested with synthetic miRNA408 (640 ng) both in distilled water and in tomato leaf extract, showing significant target inhibition in just 9 min once the reaction was started.</div></div><div><h3>Significance</h3><div>These findings represent the first RNAzyme-based paper technology for miRNA detection in crops, offering farmers digital, on-site decision-making tools. Results aid in advancing the understanding of stress response mechanisms in tomato and, potentially, in other species.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115148"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Acidic etching coupled with coordination assembly for in situ synthesis of fishbone-shaped Cu(II)-phytic acid polymer for electrochemical biosensing of microRNA-let 7a","authors":"Min Chen ,&nbsp;Yangyi Wu ,&nbsp;Qinghua Wang ,&nbsp;Qingxiang Wang ,&nbsp;Feng Gao","doi":"10.1016/j.microc.2025.115178","DOIUrl":"10.1016/j.microc.2025.115178","url":null,"abstract":"<div><div>The construction of a facile and highly sensitive electrochemical biosensor for microRNA detection has significant implications for clinical diagnostics. In this study, an interface integrating a fishbone-shaped Cu@Cu(II)-phytic acid (Cu@Cu(II)-PA) polymer was developed through in situ acidic etching coupled with coordination assembly. After further modification of electrodeposited gold nanoparticles (AuNPs), this interface served as a multiple-nanocomposite for the construction of an electrochemical biosensor for miRNA-let 7a. First, a layer of metallic copper was prepared on a glassy carbon electrode (GCE) through electrodeposition. Followed by, the acidic PA solution was dropped on the electrode, from which the metallic copper was chemically etched and the generated Cu(II) ions were reacted with PA to form Cu@Cu(II)-PA polymer through the coordination assembly. Subsequently, a layer of AuNPs was electrosynthesized on the Cu@Cu(II)-PA, acting as the matrix for pDNA immobilization. Electrochemical assays indicate that the AuNP/Cu@Cu(II)-PA composite exhibits excellent electrocatalytic activity towards H₂O₂, mimicking peroxidase. The hybridization of pDNA immobilized on the electrode surface with the target miRNA-let 7a significantly inhibits the nanozyme activity of AuNP/Cu@Cu(II)-PA, thereby enabling the detection of miRNA-let 7a based on catalytic signal variation. The analytical assay demonstrates that the target miRNA-let 7a can be analyzed over a wide concentration range from 1.0 fM to 10 nM with a detection limit as low as 0.4 fM. Furthermore, the biosensor exhibits commendable performance in the detection of miRNA-let 7a in real serum samples, highlighting its potential for clinical applications in early disease diagnosis.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115178"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperspectral imaging and machine learning-based classification and quantification of sodium saccharin in cat food powder","authors":"Zhangting Wang ,&nbsp;Tingsong Zhang ,&nbsp;Haoyuan Ding ,&nbsp;Shangyong Zhao ,&nbsp;Yan Fan ,&nbsp;Dan Qi ,&nbsp;Yujia Dai ,&nbsp;Ziyuan Liu","doi":"10.1016/j.microc.2025.115161","DOIUrl":"10.1016/j.microc.2025.115161","url":null,"abstract":"<div><div>Sodium saccharin is a synthetic sweetener occasionally added illicitly to pet food to improve palatability, yet its overuse poses health risks to companion animals. In this work, we evaluate near infrared hyperspectral imaging combined with machine learning for rapid, non-destructive quantification of sodium saccharin in ground cat food. Fifteen samples—three commercial formulations each spiked at 0, 0.05, 0.10, 0.15, and 0.20 wt% saccharin—were imaged, and mean spectra were extracted from regions of interest. Spectral preprocessing (Savitzky–Golay smoothing, standard normal variate, autoscaling) was applied to mitigate noise and scattering. We constructed qualitative and quantitative models using partial least squares regression (PLSR), random forest (RF), and a one-dimensional convolutional neural network (CNN). Among these, the SG-preprocessed PLSR model achieved the best performance on an independent test set, with calibration R² of 0.99, prediction R² of 0.98, RMSE_C = 0.08 wt%, and RMSE_P = 0.22 wt%. These results demonstrate that SG + PLSR is the optimal model across the three sample sets Therefore, SG + PLSR provides a robust approach for monitoring sodium saccharin adulteration in pet food. Our methodology offers a promising platform for inline quality control in feed manufacturing.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115161"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145004932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synchronized SERS-temperature dual signals generated from the same incident light for Immunochromatography assay of microcystin LR in aquatic products","authors":"Jianghui Zheng ,&nbsp;Cuicui Fang ,&nbsp;Mengyu Tao ,&nbsp;Bingyong Lin ,&nbsp;Yueliang Wang ,&nbsp;Yuanyuan Yao ,&nbsp;Lifen Chen ,&nbsp;Hong Huang ,&nbsp;Jianguo Xu ,&nbsp;Longhua Guo","doi":"10.1016/j.microc.2025.115195","DOIUrl":"10.1016/j.microc.2025.115195","url":null,"abstract":"<div><div>Dual-signal cross-validation enhances the reliability of quantitative measurements. However, asynchronous dual signals generated from different incident light affect the acquisition time and reliability of quantitative detection. In this work, we proposed an immunochromatography (ICA) sensor that utilizes synchronized Surface-Enhanced Raman Scattering (SERS) and temperature dual signals generated from the same incident light for analyzing microcystin-LR (MC-LR) in aquatic products. Quantitative analysis reveals a good linear correlation between the dual signals and the logarithmic concentration of MC-LR over the range of 0.001000–80.00 ng/mL. Moreover, the proposed method demonstrated excellent recovery rates and the results were similar with enzyme-linked immunosorbent assay, but the signal acquisition time (3 s) and overall detection time (10 mins) of our approach were significantly reduced. Therefore, a synchronized dual signals ICA sensor that combines SERS and photothermal technology was constructed for direct, rapid, and reliable detection of MC-LR, providing a promising application for field-based monitoring.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115195"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Incorporating silicon-doped carbon dots into europium chelated silica microspheres for the ratiometric fluorescent and colorimetric detection of Fe3+ ions","authors":"Shuting Guo,&nbsp;Lulu Liang,&nbsp;Qingzhong Guo,&nbsp;Junfang Guo,&nbsp;Huaming Zheng","doi":"10.1016/j.microc.2025.115194","DOIUrl":"10.1016/j.microc.2025.115194","url":null,"abstract":"<div><div>In this study, a novel hybrid luminescent microsphere, Si-CDs@SiO₂-Eu was designed and successfully synthesized by encapsulating blue-emitting silicon-doped carbon quantum dots (Si-CDs) into carboxyl-modified SiO₂ microsphere and coordinating with Eu³⁺ ions. The SiO₂ matrix provides a stable dispersion environment for Si-CDs and serves as an effective platform for anchoring Eu³⁺ on the surface of microsphere, thereby realizing the spatial isolation and establishing dual-emission characteristic. The dual-emission microspheres can be served as a ratiometric fluorescent probe for the detection of Fe³⁺ in water with the red emission of Eu³⁺ ion as response and the blue emission of Si-CDs as reference. It displays high selectivity and sensitivity for Fe³⁺ with a detection limit of 1.41 μM. It is worth noting that an easy-to-differentiate color change for visual detection is also observed. In addition, the luminescence quenching mechanism study reveals that absorption competition quenching (ACQ) mechanism and cation exchange cause luminescence quenching at 617 nm, but have little effect at 400 nm, thus realizing the fluorescent ratiometric detection of Fe³⁺. Si-CDs@SiO₂-Eu functions as a dual-mode probe that integrates ratiometric (quantitative) and colorimetric (qualitative) detection, enabling real-time monitoring of Fe³⁺ and enhancing detection reliability.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115194"},"PeriodicalIF":4.9,"publicationDate":"2025-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimized LC-MS/MS approach for trace detection of trans-4,5-epoxy-(E)-2-decenal: Advancing volatile organic compounds biomarker research in human","authors":"Ziyuan Zheng ,&nbsp;Wenguang Yan ,&nbsp;Wenlong Liu ,&nbsp;Zihao Cai ,&nbsp;Yanjun Ding ,&nbsp;Jiang Ling","doi":"10.1016/j.microc.2025.115166","DOIUrl":"10.1016/j.microc.2025.115166","url":null,"abstract":"<div><div>Volatile organic compounds (VOCs) play a critical role in human physiology, with their concentrations serving as key indicators of physiological states. Among these, trans-4,5-epoxy-(E)-2-decenal, a volatile organic compound found in mammalian blood, exhibits unique chemical reactivity and olfactory sensitivity due to its molecular structure, which is closely associated with lipid peroxidation processes. However, conventional detection methods, such as gas chromatography-olfactometry-mass spectrometry (GC-O-MS), suffer from limitations including inherent subjectivity, poor reproducibility, stringent operational requirements, and low throughput, which undermine their clinical reliability. To address these challenges, this study developed an optimized liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for accurate qualitative and quantitative analysis. Given the poor detectability of aldehydes via LC-MS/MS, 2,4-dinitrophenylhydrazine (DNPH) derivatization was employed to enhance the chromatographic behavior and retention of the target compound. Additionally, HLB solid-phase extraction (SPE) columns was employed for purification to enhance the sensitivity of LC-MS/MS for the detection of trans-4,5-epoxy-(E)-2-decenal. Following derivatization, trans-4,5-epoxy-(E)-2-decenal demonstrated strong retention during chromatographic separation. The mobile phase, composed of acetonitrile and ultrapure water, exhibited significantly superior performance compared to combinations of acetonitrile with ammonium acetate buffer. Under optimized conditions, the LC-MS/MS method demonstrated excellent linearity for trans-4,5-epoxy-(E)-2-decenal within a range of 1–300 ng/mL, with correlation coefficient (R²) of 0.9984, detection limit (LOD) of 0.3 ng/mL. The relative standard deviation (RSD) for spiked blood samples in the experiment was 12.53 %.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115166"},"PeriodicalIF":4.9,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aggregation-induced emission Ru(II) complex nanomaterials: Phosphorescent determination of alkaline phosphatase activity and inhibitors","authors":"Qianghui Zheng,&nbsp;Jinyuan Zhang,&nbsp;Mei-Jin Li,&nbsp;Fengfu Fu","doi":"10.1016/j.microc.2025.115191","DOIUrl":"10.1016/j.microc.2025.115191","url":null,"abstract":"<div><div>Alkaline phosphatase (ALP) is a vital protein catalyst that holds a central role in modulating protein metabolism and function throughout organisms, and serves as a reliable foundation for the treatment of human diseases. Thus, the development of a sensitive and selective detection strategy for ALP is considerable scientific and practical significance. In this study, SiO₂ was chosen as the carrier for encapsulating Ru-1 luminophores to effectively prevent the leakage of Ru-1 molecules. Meanwhile, during the preparation process, the introduction of a poor solvent induces aggregation of Ru-1 molecules into nanoparticles, thereby enhancing emission through the aggregation-induced emission effect. Furthermore, using an in-situ growth method，we developed a phosphorescence-based detection strategy, which builds on Ru-SiO₂-MnO₂ nanocomposites. <span>l</span>-ascorbic acid (AA) can be generated by ALP, which catalyzes the hydrolysis of sodium L-ascorbyl-2-phosphate (AAP). This process further breaks down MnO₂ and triggers the phosphorescence sensor through a “turn-on” mechanism. Moreover, by exploiting the capacity of Na₃VO₄ to suppress ALP activity, this phosphorescent method was further employed for the identification of ALP inhibitors. Under the optimized experimental conditions, the phosphorescent intensity displayed a linear association with ALP concentrations ranging from 0.05 to 17 U/L, while the limit of detection was as low as 0.031 U/L. The proposed strategy eliminates the need for complex washing or modification procedures and avoids the aggregation-caused quenching phenomenon of traditional organic dyes, thus standing out as an uncomplicated, economical “turn-on” phosphorescent detection method for ALP. This approach also demonstrated excellent applicability in the analysis of serum samples.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115191"},"PeriodicalIF":4.9,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid and facile synthesis of nitrogen-doped carbon dots for fluorescence-smartphone dual-mode detection of doxycycline and anti-counterfeiting applications","authors":"Xintong Yang ,&nbsp;Yating Meng ,&nbsp;Zhenhua Yang ,&nbsp;Xuansen Sun ,&nbsp;Yuexia Zhang ,&nbsp;Chuan Dong","doi":"10.1016/j.microc.2025.115190","DOIUrl":"10.1016/j.microc.2025.115190","url":null,"abstract":"<div><div>The extensive use of antibiotics in livestock has raised concerns regarding the potential presence of harmful residue levels in animal feed and food products. Herein, nitrogen-doped carbon dots (N-CDs) are rapidly synthesized via pyrolysis with citric acid (CA) and tris(hydroxymethyl)aminomethane (Tris) as precursors. The N-CDs exhibit optimal excitation/emission at 359/429 nm and a quantum yield of 56 %. A novel fluorescence sensing system based on smartphones has been created for the dual-mode detection of doxycycline (DC) by utilizing the inner filter effect (IFE) to quench fluorescence. The platform shows two linear ranges of 1.5–16.7 μM and 16.7–66.8 μM, with corresponding limits of detection (LOD) of 0.45 and 0.81 μM, respectively. The method quantifies DC in milk samples with recoveries of 98.80 %–103.90 %, validating its accuracy and practicality. Furthermore, the N-CDs enable DC monitoring in human hepatocarcinoma cells (SMMC-7721) and zebrafish, owing to their minimal toxicity and outstanding biocompatibility. Interestingly, the N-CDs embedded in the filter paper have remarkable thermal stability in the range of 20–100 °C, even after being heated at 100 °C for 60 min. Their outstanding optical properties enable their use in invisible ink for encryption and anti-counterfeiting. This dual-mode platform has shown significant potential in environmental monitoring and advanced security technologies.</div></div>","PeriodicalId":391,"journal":{"name":"Microchemical Journal","volume":"218 ","pages":"Article 115190"},"PeriodicalIF":4.9,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}